Ojala means hope.
Please check back later as I'm sure SraJMcGin will had more information.
How is it different from esperar?
Thank you for using the Jiskha Homework Help Forum. I've never heard the WEIRDO but it's "catchy!" I'll explain it to you as I always explain it!
Let's begin with ˇOjalá! This came from the Arabic "Oh, Allah...grant that I be rich. Oh, Allah...grant that I be famous, etc." The Spaniards picked up on "Oh, Allah" and it becah "Ojalá." Say it outloud and I'm sure you'll understand.
How is it different from "esperar?" The expression "Ojalá" stand alone and is the one time in Spanish when the Subjunctive is not introduced by "que." You will hear/say Ojalá que no llueva. (I hope it doesn't rain.) OR Ojalá no llueva. They are the same as "Espero que no llueva." However, "esperar" is a conjugated verb and must have a personal ending on it = o, as, a, amos, an = depending upon WHO is wishing.
Now to the Subjunctive. I used to draw on the board a locamotive + que + caboose. I can not draw here but that represents SUBJUNCTIVE + (clause relater) QUE + SUBJUNCTIVE. It is the MAIN VERB which determines whether you have the subjunctive or not. You need to classify it as: 1. will, wish, imposition of will (1 person wants another to do something but that doesn't make it FACT) or 2. emotion or 3. doubt, disbelief, denial or 4. judgment (many impersonal expressions) or opinion. The "que" represents a "trailer hitch" and the caboose is where you have the Subjunctive. (riding along for the ride) In other words, the Main Verb is in the Independent Clause (can stand alone) but the Subjunctive is in the DEPENDENT Clause. (it is dependent upon the main verb as to whether it exists or not)
In ONE word the INDICATIVE states FACT while the SUBJUNCTIVE states FICTION/MAYBE/ CONTRARY-TO-FACT. Imagine a crystal ball if you will. If you can see that it DOES happen (Present tense), WILL happen (Future), DID happen/was h appening (Past, either Preterit or Imperfect), HAS happened (Perfect Tense), etc. it is NOT Subjunctive. If, however, the crystal ball is cloudy and you can NOT see what happens, happened, etc. for certain, it is Subjunctive!
When you say you don't understand the "last one" I don't know to what you are referring. Please clarify.
Just give it time, keep asking yourself "fact or fiction" and try some examples. If you'd like a "list" of verbs, impersonal expressions, using the Subjunctive, just ask!